Method for fabricating propeller blades and the like



Oct. 20, 1936. w SMlTH 2,057,924

METHOD FOR FABRICATING PROPELLER BLADES AND THE LIKE Filed 00tl, 1929 9Sheets-Sheet 1 Q 5 a; g N e Q \h 1 N N I V I I Oct. 20, 1936. J, w, s T2,057,924

METHOD FOR FABRICATING PROPELLER BLADES AND THE LIKE Filed Oct. 1, 19299 Sheets-Sheet 2 Q Q INVEN TOR T NEY V I1. 62m

J. W. SMITH METHOD FOR FABRICATING PROPELLER'BLADES AND THE LIKE F-iledOct. 1, 1929 9 Sheets-Sheet 3 INV TOR.

Oct. 20, 1936. w sMlTH 2,057,924

METHOD FOR FABRICATING PROPELLER BLADES AND THE LIKE Filed Oct. 1, 19299 Sheets-Sheet 4 Jig. 5

m ww- Oct. 20, 1936. J. w. SMITH 2,057,924

METHOD FOR FABRICATING PROPELLER BLADES AND 'THE LIKE Filed Oct. 1, 19299 Sheets-Sheet 5 aw A ORNEYS.

Oct. 20, 1936. J. w. SMITH 2,057,924

' METHOD FOR FABRICATING PROPELLER BLADES AND THE LIKE Filed Oct. 1,1929 9 Sheets-Sheet 6 fi ORNEYS.

Oct. '20, 1936. J. w. SMITH 2,057,924

METHOD FOR FABRICATING PROPELLER BLADES AND THE LIKE Filed Oct. 1, 19299 Sheets-Sheet 7 IN VEN TOR.

J. W. SMITH Oct. 20, 1936.

METHOD FOR FABRICATING PROPELLER BLADES AND THE LIKE Filed 001;. l,

1929 9 Sheets-Sheet 8.

M INVEN 0R.

ATTORNEYS.

Oct. 20, 1936. J. w. SMITH 2,057,924

METHOD FOR FABRICATING PROPELLER BLADES AND THE LIKE Filed Oct. 1, 19299 Sheets-Sheet 9 Patented a. .20, 1936 PATENT OFFICE DIETHOD FOEFABRICATING PROPELLER BLADES AND THE LIKE John W. Smith, Philadelphia,Pa. Application October 1, 1929, Serial No. 396,481

My present invention relates to a machine and method for makingaeronautical propeller blades, fabricated by combining threefundamentals, forging, longitudinal .rolling and simultaneous twistingas a completed stage .of fabricating a metal propellerblade and isapplicable to and an improvement upon my co-pending U. S. pat

ent application Serial No. 289,052, filed June 28, 1928, issued asPatent No. 1,840,059 on January 5, 1932, entitled Rolling machine.

f The specific type of blade herein referred to is fabricated fromaicomparatively short billet and within the completed forging andlongitudinal rolling period andis distinctively diiferent from theheretofore used method of forming and twisting or shaping propellerbladesafter the forging period or after the cross sectionalarea andlength have been prepared. a Attempts to fabricate propeller blades byform; ing, shaping and twisting prepared metal blanks after the requiredcross sectional area and length have, been prepared by forging orrolling has resulted in structural weaknesses.

There are two important factors to be con-- sidered 'in making the bestpossible metallic aeronautical propeller blade suitable for modern highspeed performance.

The first factor relates tothe specific type of blade. 30 The secondfactor relates to the apparatus and method of fabricating the specifictype. of blade. two factors cannot be properly explained when treated asseparate'subject matter.

.The above two factors must be combined in 35 the manufacture ofthe bestpossibleaeronautical propellers; v

In my other application Serial No. 289,052 I showed a machine inwhich itwas necessary to hand-tilt, or set the die l5at the time when the 40blank was inserted.

. I'now. employ an automatic means in the form of small auxiliaryrollers 63, Fig. 7, for positively controlling the tilting of the die l5during the I initial pass or passes and before'the gauging V 45 rollersla and lb make contact with the rails lib of the tilting die. p

Improved means, Figs. 4 and 6, comprising rod 44, crank 45a, rod 48, andracks llaand 41b, are herein employed for adjustably settingthe an- 50nulardie l4 toward the other die as a substitute for the setting meanscontrolled by the hand lever II in the'machine of my other application.I

As a modification I retain the fundamental which combines the forging,rolling and twist- 56 ing operation of my other machine, but substitutefor the longitudinally reciprocating tilting die a second annular dieand axially twist the metal blank instead of said die, or tilt theannular die and hold the blank.

These and other advantages of my present in- 5 vention will appear fromthe following specification and drawings showing a preferred embodiment.

In these drawings:

Fig. 1 shows a comparatively short metal blank 10 suitable for formingtwo blades. Fig. 1B is a cross section of same.

Fig. 1A shows an initial forging operation applied to one of saidblanks.

Fig. 2 is an end view combined with a plan view of the finished blade,the latter also showing cross sections of the blade taken at variouspositions' along its length.

justing means therefor, the latter operable to vary the extent of theforging movements of the annular die.

Fig. 6 is a transverse vertical sectional view partly in elevationthrough the machine of Fig. 4 showing 'the driving gears of the machine,the means for controlling the extent of the forging movements of theannular die, and the means for operating the walking beam whichreciprocates. the tiltable dieduring rolling period. 40

Fig. 6A shows means for setting for first or second pass.

Fig. 7 is a transverse vertical sectional view partly in elevation on alarger scale than Fig. 4

showing the annular die and the transversely tiltable longitudinallyreciprocating die in position for the final passes with a section of thepropell blade in the die cavity. v

Fig: 8 shows crank pin adjustment for second pass. I I

Fig. 9. shows tension adjustment for gauging rollers. I

The remaining Figs. 10 to 16 show the double annular die modification ofthe machine asfollows:

Fig. 1c is a view similar to Fig.4 except that an annular die has beensubstituted for the iongitudinally reciprocating die and shows the meansfor supporting and axiallytwisting the Fig. 12A is a plan .view of theturning mecha-- nism of Fi 12.

Fig. 13' a sectional view partly in elevation through the two annulardies and their related parts.

Fig. 14 is an end view of the annular dies partly in section and theirrelating; parts. Fig. 15 is a transverse vertical sectional view partlyin elevation on a larger scale through the pitch generating mechanism.

Fig. 16 shows a substitute for the means of Figs. 13 and 14 by providinga tilting mounting for one of said annular dies.

'Fig. 1'? shows a further substitute for the means of Figs. 13 and 14. aI will now describe the specific mechanism as a typical example forforging, rolling andsimultaneously twisting the metal blank into thefabricated article but of course without limiting my invention to thedetails of said embodiment except as required by the appended claims inview of the prior art. The same reference numerals indicatecorresponding parts throughout.

The base 60, Fig. 4, of the machine supports col- .umns 68:: connectedat the top by cap-yoke 60b.

This supports the toggle means hereinafter described for giving verticalforging movement to the head 58, the latter having sleeves 58a slidableon the columns 69a. This head 58 supports slightly higher (Fig. 7) thanthe sidewalls [5a of the die cavity to permit the excess metal from theblank to squeeze from between the annular 'die 14 and the die l5'intothe aforesaid flash re-.

4 .cesses 6. The surface of the rails l5b and of the blade tobe formed.

die-cavity walls l5a lie in an undulating twisted plane corresponding tothe angular twist of the The die I5 is mounted for longitudinalreciprocation under the-annular die l4 and for simultaneous lateraltilting movements so that the twodies cooperate on a plane which followsand ultimately is identical with the above described twist in the railsand die.

. Extra heavy toggle link construction is used to secure the necessaryvertical forging pressure of the annular die l4 against the metal blankand the lower die l5. Thus the described cross-head 58 supporting saidannular die is supported'by toggle links 38a, and 36b, pivoted to therockers r 31a and 3") by pins 36, the links being pivoted to thecrosshead by the pins 31. The rockers 3H: and 3 b are connected by link38. The means :for

operating said toggle comprises an armed rock-r shaft 53, Fig. 4,suitably journaled in the machine housing 8! and 82 and having aleft-hand arm for mounting the cam roller 49 and a right-hand armconnected by link 52 with the upper parts of the rockers 3la and Nb.When the circular faced cam 50 on the anti-clockwise rotating shaft I0bears against the aforesaid cam roller 49,

Fig. 4, it rocks the armed rock-shaft 53, pulls down on the link 52 andstraightens the toggles which forces the annular die M with a powerfulforging movement into the metal blank. Then said annular die l4 remainsin said down position while the walking beam 56 imparts reciprocatingmovement to the die I5. Said crosshead is not released until the liftingcam 5| carried by cam shaft 10 contacts against the cam roller 56mounted on an arm of the rock-shaft 53. By

pushing upwardlythe link 52 the toggles are unlocked and the roller dieI4 is withdrawn from 'die l5.

Die i5 receives reciprocating movement through walking beam 56 hinged onpin which is securely fastened into main housing 8| as shown in Fig. 6and Fig. 3.

Crank pin 55c is journaled in a shoe slidably guided in walking beam 56as in my other application.

Crank pin 55c is a part of slide 55a (Fig. 6) mounted on the rotatingcam shaft 18.

' Adjusting screws 55b control the adjustment of crankpin 550 shown inFigs. 4 and 6, and provide for the required length of travel for makinglong or short forgings. I

It will thus be seen that when the shaft vIll is driven, the walkingbeam 56 will be oscillated re-.

sulting in the longitudinal reciprocation of the die carriage 59 alongwith the cradle 20 and the rest of it being indicated merely by thebroken Adline 56 so as not to obstruct the drawings. justable link 51connects walking beam 56 with reciprocating carriage 59.

The walking beam construction provides an extended time element of 235(compare Fig. 2B) for the rolling stroke and a short time-element for aquick return'stroke of 125. I

Rack 59 in Figs. 4 and 7 is hinged by link 88 to adjustable stud mountedin arm 89 which is fastened to and reciprocates with reciprocatingcarriage 59.

Rack 59 reciprocates in' gear case 58a (Fig. 7) and is in mesh'with gearwheel 64 which is secured to annular die shaft 8 by bolt 81. Annular dieIt is secured to shaft 8 by key 69. The herein described mechanismestablishes a registration between the reciprocating die l5 and annulardie- I 4 and provides for a vertical forging movement during the restperiod of the reciprocating die i5.

Two or more automatic passes of different forging'extent are providedand are made to function through the following mechanism.

In Figs. 4 and 5, toggle rockers Sla and 3lb are mounted on shafts 35aand 35!), supported at .either end in eccentric bushings 34 (Fig. 5)which are journaled in supporting cap rocker 39 and securely held toshafts 35a. and 35b.

Lever 48, shown in Fig. 5 (center line of same is. shown in Fig. 4) issecured on shafts a and 35b,

and may bemoved from position 42a to 421) shifting center from 53a and59b. thus automatically setting the machine for the first and secondpass respectively. thus automatically setting the pass during liftingperiod-C, shown in diagram Fig. 23 at a time when there is no pressureon the dies.

In Figs. 4 and 6, shifting link 48 is shown to be hinged to cam rocker53. Cross pin 4% forms a part of link 48 and operates in guide slot.69(Fig. 6A and Fig. 6) and is used to shift pin 48b from rack hook 41a to411), and vice versa, the shifting medium is represented by lever 61.Tumble shaft 68 is pivoted into guide 69 as shown in Fig. 6A.

Teeth on racks 41a and 41b shown in Figs. 4 and 6 engage pinion 46,secured to crank shaft 450. When rack 41a is pulled down as hereindescribed crank pin 45 will be in position for the second pass. Whenrackjl'lb is pulled down crank pin 45 will bein position shown in dottedlines at 45b for the first pass. Link 44 transmits from crank pin 45 tolever 40 the required movement for the first and second pass.

Fig. 8 shows how crank pin 45 is slidably fitted into the crank end ofcrank shaft 45a. Adjust- I the crank pin 550 is passing the neutralpoint-of the stroke, said crank pin rotating in anti-clock ing screw 45bis used for setting the crank throw to suit the required amount ofreduction for the second pass.

In Fig. 4 if the throw of crank pin 45 is increased the are between 53aand 53b will be increased. If thethrow of crank pin 45 is diminished,the are between 53a and 53b will be diminished.- If lever 61' is notmoved, the pass will be automatically repeated.

In most cases the second pass would be repeated as the final pass. I 1

Fig. 7 shows the gauging rollers 1a and lb bearing hard against the dierails l5b, which represents a requirement for the final pass in rollingto gauge thickness and unit weight.

Auxiliary. rollers 63 are mounted in suitable sockets in brackets 52aand 62b secured to the main housing 60 and control the tilting of thedie l5 when the gauging. rollers la and lb are withdrawn.

A large forging machine has considerable spring to be considered.

The second pass may result in the gauging rollers la and lb being forcedaway from the rails l5b, where the blade is widest, thus requiring arepeating pass to finish to gaugev thickness.

Fig. 9 shows the length of link 44 to be adjustable by means of rightand left hand screw threads. This adjustment is made use of to securethe proper tension for gauging rollers la and lb.

The described shifting of the arm 48 from one rack to the other may bemade either by hand or automatically.

Fig. 7 shows how the die cradle 20 along with the die I5 is free to tiltto dotted line positions 6M and Bib to conform to the required pitchangles throughout the blade profile. The face of the die I5 ispreferably machined on a special pitch-generating miller as shown in myU S. patent application, Serial No. 268,208, filed June 4, 1929.

The diagram,'Fig. 23, indicates a typical example in the operation of mymachine of vertical forging and longitudinal rolling divided into fourperiods A, B, C. and D.

Period A shows the vertical forging movement to be substantiallycompleted within the dwellperiod of walking beam 56 at the moment whenwise direction. The rolling period '3 then takes place during 235 out ofone complete rotation or cycle.of the crank pin. 'At the finish of thelongitudinal rolling movement, the annular die I4 is raised from thework, this being the lifting period 0 in the diagram. Within the fulllift period D the machine may be stopped, if desired,

by moving hand lever 18, Fig. 6, thus disengaging the clutch l6. Atthattime the annular die M will be raised sufliciently high to withdraw thefinished blade and a new blank l0 may be inserted.

Fig. -1A shows the blank in position between the two dies l4 and I5. Thevertical forging movement has forced die M in the direction of arrow l3for the first pass. Space l2 between dotted line of annular die I4 andreciprocating die l5 represents the amount of reduction left for thesecond pass.

The stop is serves to locate the blank with relation to the dies and italso obstructs the flow of metal toward the hub end of the blank duringthe forging operation. The blank is gripped by causing the jaws Ilia andllib to be forced into the blank.

This gripping takes place during the forging movement as follows:Shoulder 22 on roller l4 forces gripping jaws I61: and llib to fullgrippin position as shown in Fig. 3. 1

Handle l'lb is a means for unlocking toggle I and l8b and also lifts theforging out of the die I 5 by imparting a movement to l6a and lib shownby dotted lines. Any suitable means can be used for'grlpping the blankat its near end.

I prefer to use this character and form of blank although it will beunderstood the same is not strictly essential. In other words, theproper distribution of the metal throughout the blank to form the bladeby my method and machine is secured, preferably by sawing it off on anincline asshownat H in Fig. 1.

In this application as in my Patent No. 1,840,059, the metal is urged ina longitudinal direction at the moment of deforming, and each rollingpass starts at the required pressure and this required pressure ismaintained throughout the rolling period. I

Each pass starts off with a vertical die forging movement for preparingtheheavy section of the blade at the butt end of the blank. Upon thecompletion of the verticalforging movement and without releasing it, alongitudinal rolling movement takes place at the required pressureextending lengthwise of the bar, thus preparing a longitudinal grainfibre in the blade structure with a simultaneous shaping and twisting ofthe blade. By my method and machine the finished blade, Fig. 2, comparedwith the blank Ill is considerably elongated, preferably so that thegrain fibre'is extended longitudinally in the ratio of about oneto'three. The zone of the blade subject to the highest strains willpossess the most extension of grain fibre.

The above process of forging, rolling and twisting prepares in the bladethe very best physical properties."

The face of the annular die I4 is shown channeled at Ma to prepare theupper face of the blade during the forging and rolling operations. I hemetal of said blank is squeezed and-rolled down into the cavity of thedie l5. These forging and rolling passes are repeated until the dieforging movement of the annular die completed and the machine about tobegin the second pass rolling movement. This pass may be repeated as afinal pass.

It will be seen that the described method and machine rolls the bladeprofile from a comparatively short billet, establishing the width,thickness, length and twist as a simultaneous operation. This isdistinctively diiferent from the prior art methods of preparing theangular twist of the blade after the length and cross sectional ureahas'been prepared, said prior art methods resulting in a comparativelyinferior finished blade.

My application Serial No. 289,052 has the equivalent vertical forgingand longitudinal rolling movements, the operation of same was explainedin connection with a specially prepared short blank requiringconsiderable longitudinal rolling and only a slight amount of verticalforging.

This invention is herein further explained in connection withfabricating propeller blades from plain round bar material which is lessexpensive.

The vertical forging movement is herein used to eliminate the necessityof previously shaping the blank at the forging zone between lines 24 and25 Fig. 2.

Figs. 2 and 2A show one type of finished blade adapted to be fabricatedby my method and process. The round portion between the lines 23-24 ispreferably finished by machining the blade. The zone between the lines2425 is die forged. The zone between line 25 and the end 26 is die.rolled to gauge cross section and unit weight including angular twist.Forging, rolling and simultaneously twisting by using double annulardies Fig. 10 makes use of the same fundamental vertical forging andhorizontal rolling as shown in Figs. 1 to 9 inclusive, by substitutingannular die I50 for horizontal die I5. Therefore, no further descriptionis considered necessary.

Figs. 13 and 14 show the equivalent rack mechanism used for theregistration ofv said annular dies.

Fig. 14 shows 59a and 59b to be hinged on wrist pin I09 mounted inreciprocating carriage IIIl.

Connecting link 51 is also mounted on wrist pin I09 imparting motionfrom walking beam 56 to reciprocating carriage IIIl.

Annular die I50, substitutes reciprocating die 65 shown in Figs. 7 and4.

Fig. 16 shows annular die I 5d mounted in nonreciprocating cradle 20awhich is seated in main housing; in this event the pitch'angle isgenerated on the annular 'die I5d, and would eliminate the use of pitchgenerating mechanism shown in Fig. 11. Gripping jaws H3 would berequired to reciprocate without rotary motion. 'In this event I25, Fig.11, would be set parallel to the reciprocating path, as shown in dottedline I25a.

Fig. 17 shows annular dies .I5e and Me to have the pitch angle generated'onthe face of both annular dies,in this modification annular diesarenot tiltablymounted and would be used with a non-rotating grippingmechanism for holding the blank. Q

The above annular dies have milled in their faces the blade profile.

The required pitch -is generated by rotating the gripping jaws with thefollowing mechanism in the herein described manner.

- Blank III (Fig. 1) is firmly held between rip- Pins jaws II3 pivotedon pins II3a as shown in Fig. 10.

T ggle links I I4. and rocker 5 are actuated by piston I" through linkIIG.

Gripping jaws H3 and rocker II5 are mounted in sleeve I I2, which isfree to rotate in reciprocated housing IIII.

-Spur gear H8 is mounted on sleeve H2. and engages with pinion II9 whichis fastened on pinion shaft I20. I

' Bevel pinion I2I is mounted on pinion shaft I20 and engages bevel gearI22 which is bolted to pitch generating arm I24 as shown in Fig. 10 andFig. 11. Generating slide I25, Fig. 10, is adjustably mounted on arm I24by means of pivot bolt I23 and bolt I28 in slotted hole I33.

Bracket I3I is fastened to main frame 63 for supporting cross bar I26 inwhich'shoe I2I is pivoted, as also shown in Fig. 9.

Housing III is provided with a pair of tru'nr nions I08 and reciprocateswith carriage IIII.

Studs I09 are mounted on reciprocating carriage I I 0 to which forkedlink 51 is hinged and is reciprocated by walking beam 56.

Racks 59aand 59b are also .hinged to the studs I33 and are actuated bythe same motion.

Figs. 13 and 14 show how racks 53a and 53b engage timing gear wheels 64aand 54b respectively. The annular dies I4 and.I5c are securely mountedon shafts 8a and 81). Gear wheels 34a and 64b are securely mounted onshafts 8a and Rocking shoe 4 in Figs. 13 and 14 provides for theswinging of rack 59b during vertical forging movement of annular die I4.

Fig. 1-2 shows a modified movement which may be substituted for thepitch generating movement. Rocking head I3'I is secured to bevel gearI22. Actuating link I33 is mounted on stationary cross bar I3I.

The rocker head I3'I has been rotated from pivot point I38 to positionI39 at the end of-the stroke after the completion of the rollingmovement.

Link I33 may be set to angle I34 by hand operated handle I35 forreturning rocker head I31 to normal position thus causing gripping jawsII3 to receive right angle turns at the completion of each pass, makingit possible to. roll various tapered or special shapes.

I claim:

1. The method of making a propeller blade, comprising rolling a billetof metal into rough blade shape l'v a series of complete rolling passesfrom the I001. portion to the tip portion of the blade, thereby creatingflow lines conforming to the contour of the blade, and completing theshaping of the blade by operations maintaining such fiow line structure.

2. The method of making a propeller blade, comprising deforming a billetof metal into rough blade shape by the repeated application of adeforming force progressively advancing from the root portion to the tipportion of the blade, thereby creating fiow lines in the metalconforming to the contour of the blade and confined within a deformingforce to the metal, progressively advancing the point of application offorce from the root portion to the tip portion of the blade,progressively applying the required force from the root portion to thetip portion of the blade to gradually refine the grain structurethroughout the length of the blade with a of grain size contrast and toform fiow lines conforming to the contour of the blade, and completingthe shaping of the blade by forging operations without increasing thegrain size contrast or destroying the fiowlines.

4. The method of making a propeller blade, which consists in rolling abillet of metal to prepare longitudinal flow lines in it, rolling saidbillet into rough blade shape by a series of complete rolling-passesfromthe root portion to the tip portion of the blade, thereby creatingflow lines conforming to the contour of the blade, and completing theshaping of the blade by operations maintaining such fiow line structure.

5. The method of making a propeller blade, which consists in preparinglongitudinal flow lines in a billet of metal by rolling, deforming saidbillet into rough blade shape by the repeated application of a deformingforce progressively advancing from the root portion to the tip portionof the blade, thereby creating flow lines in the metal conforming to thecontour of the blade and confined within the blade, and completing theshaping of the-blade by operations maintaining such flow line structure.

6. The method-of making a propeller blade, which consists in preparinglongitudinal fiow lines in a billet of metal by rolling, graduallydeforming said billet into the shape of a tapering blade by applying adeforming force to the metal, progres'sively advancing the point ofapplication of said force from the root portion to the tip portion ofthe blade, progressively applying the required I force from'the rootportion to the tip portion of the blade to gradually refine the grainstructure throughout the length of the blade with a minimum of grainsize contrast and to form fiow lines conforming to the contour of theblade, and completing the shaping of the blade by forging operationswithout increasing the grain size contrast or destroying the flow lines.

7. The method of fabricating a propeller blade and the like from acomparatively short metal blank, which consists in subjecting said blankto an initial forging operation, urging the metal in a longitudinaldirection at the moment of deforming as a preparation for longitudinalrolling, subjecting said blank to longitudinal rolling, and

simultaneously twisting the blank conformably to the axial twist of theblade, whereby the physical properties of the blade are improved and alongitudinal fiber structure is incorporated therein.

8. The method of claim 7, further characterized by repeating the cycleof operations therein set forth to further improve the physicalproperties and secure unit weight and precision in the finished article.1

9. The method of fabricating propeller blades and the like, whichcomprises applying a forging operation near one end of a metal blank inreduction of its thickness, substantially obstructing the free fiow ofthe metal during said forging operation towards the near end of saidblank but not towards the far, end, and applying'rolling and shapingoperations lengthwise of said blank thereby developing the longitudinalfiow line to conform to a predetermined die cavity.

10. The method of fabricating propeller blades and the like from a shorttaper ended metal blank, which comprises applying the required forgingpressure near one end of the blank in reduction of its thickness, andapplying rolling and shaping operations lengthwise of said blank withoutreleasing the required forging pressure thereby developing thelongitudinal fiow line to conform to a predetermined die cavity.

11. The method of fabricating propeller blades and the like, whichcomprises subjecting a short metal blank with one end tapered to aforging operation in reduction of its thickness, and to simultaneousrolling and shaping operations lengthwise of the blank starting fromsaid reduced in thickness part and rolling towards said tapered end.

12. The method of fabricating a propeller blade and the like, whichcomprises sawing or otherwise cutting at an angle a rolled metal blank,subjecting said blank adjacent to the opposite end to a forgingoperation in reduction of its thickness, and starting from said reducedin thickness zone simultaneously rolling, shaping and twisting the bladeto the required thickness.

13. A method of fabricating propeller blades or the like, which consistsin placing a metal blank shorter than the finished blade between twodies formed with die cavities corresponding to the shape of the finishedblade, at least one of the dies being a roller, forcing the two diestogether with sufficient pressure to produce a forging effect on onepart of the blank, thereby forming aportion of the blade adjacent itshub end, and then causing the roller die to press the blank against theother die while moving the blank relative to the roller withoutreleasing the forging pressure, thereby rollingxand drawing the metaltoward the tip of the propeller blade, producing a favorable grainstructure to conform to a pre determineddie cavity.

14. A method of fabricating propeller blades or the like, whichcomprises placing a metal blank shorter than the finished blade betweentwo dies formed with die cavities corresponding to the shape of thefinished blade, at least one of the dies being a roller, forcing the twodies together with sufficient pressure to produce a forging effect ononepart of the blank, thereby forming a portion of the propeller bladeadjacent its hub end, causing the roller die to press the blank againstthe other die while moving the blank relative to the roller withoutreleasing the forging pressure, thereby rolling and drawing the metaltoward the tip of the propeller blade, producing a favorable grainstructure and forcing the metal into the die cavities, and passing theblank through the dies a plurality of times, the distance between thedies being reduced on a subsequent pass. v

15. A method of fabricating propeller blades or the like, whichcomprises severing a cylindrical piece of metal along a diagonal line,thereby producing a blank shorter than the finished blade and having asquare-cut end and a tapered end, placing the blank between two diesformed with die cavities corresponding to the shape of the finishedblade, at least one of the dies being a roller, securely gripping thesquare-cut end of the blank, forcing the two dies together withsufiicient pressure to form a portion of the hub end of the propellerblade, and then causing the roller die to roll over, the blank towardthe tapered end of I the blank without releasing the forging pressure,

tip of the propeller blade, producing a favorable grain structure andforcing the metal into the die cavities.

16. A method of fabricating propeller blades or the like, whichcomprises placing a metal blank between a flat die and a roller die,anchoring one end of the blank at one end of the flat die, forcing theroller die against the blank adjacent the anchored end of the blank withsuflicient pressure to produce a-forging effect, thereby forming a.

portion of the propeller blade adjacent its hub end, subsequentlycausing the roller to move over the-blank and the fiat die withoutreleasing the forging pressure, and simultaneously tilting the flat dierelative to the roller die, thereby rolling and drawing the metal towardthe tip of the propeller blade, producing a favorable grain structureand shaping the propeller blade.

17. A method of fabricating'propeller blades or the like, whichcomprises placing a metal blank between two roller dies, gripping oneend of the blank, forcing the roller dies together against the blankadjacent the gripped end. of the blank with sufiicientpressure toproduce a forging effect,

thereby forming a portion of the propeller blade adjacent its hub end,and subsequently passing the blank through the roller dies withoutreleasing the forging pressure, thereby rolling and .drawing the metaltoward the tip of the prothe roller dies without releasing the forgingpressure, thereby rolling and drawing the metal toward the tip of thepropeller blade, producinga favorable grain structure and shaping thepropeller blade. I

19. A method of fabricating propeller blades or the like, whichcomprises placing a metalblank shorter than the finished blade betweentwo dies formed with die cavities corresponding to the shape of thefinished blade, at least one of the dies being a roller, the blank beingcontacted at the hub end y an abutment which obstructs flow of the meal, gripping the blank adjacent the hub end, causing the roller die tocontact with the blank at a point adjacent the hub end with sufficientpressure to produce a forging effect and to force the metal into the diecavities, and then causing the roller die to roll to the blade tip atthe required pressure, thereby diepressing the metal at the hub end androlling the blade from the hub to the tip'by one continuous,uninterrupted process.

20. A method of fabricating propeller blades or the like, whichcomprises placing a metal blank shorter than the finished blade betweentwo dies formed with die cavities corresponding to the shape of thefinished blade, at least one of the dies being a roller, the hub end ofthe blank being placed against a stop, which serves to locate the blankrelative to the dies andto obstruct flow of metal, gripping the blankadjacent the hub end, causing the roller die to contact with the blankat a point adjacent the hub end with sufficient pressure to produce aforging effect and to force the metal into the die cavities, and thencausing the roller die to roll to the blade tip at the requiredpressure, thereby die-pressing the metal at the hub end and rolling theblade from the hub to the tip by one continuous, uninterrupted process.

JOHN W. SMITH.

